Offshore Anchor Flushing System for Sediment Liquefaction

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Solution Overview

Problem

Existing anchor systems for offshore structures face challenges in securely burying and retrieving anchor devices from the seabed, particularly in deep water depths, and may become insufficiently anchored due to currents or earthquakes, posing risks to the structures.

Innovation Solution

An anchor system with a flushing arrangement integrated into the anchor base body, featuring an inlet opening for a flushing fluid and an output nozzle to facilitate the ejection of the fluid, which softens and liquefies surrounding sediment, allowing for easier burial and retrieval of the anchor device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If anchor devices are buried deep in the subsea floor to ensure secure anchoring, then anchoring reliability is improved, but excavation and retrieval become significantly more difficult and costly

Engineering Contradiction:
Improveanchoring reliabilityVSAvoidexcavation difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies hydraulic flushing systems that inject high-pressure fluid through nozzles to erode and remove sediment surrounding the anchor device. This hydraulic action enables efficient excavation and retrieval of deeply buried anchors without requiring complex mechanical digging equipment, thus resolving the contradiction between secure deep anchoring and easy retrieval.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Ease of manufacture

If anchor devices are left exposed or shallowly buried, then excavation and retrieval become easier, but the anchoring becomes insufficient due to currents or earthquakes, posing risks to the structure

Engineering Contradiction:
Improveretrieval easeVSAvoidanchoring sufficiency
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The hydraulic flushing system allows controlled burial depth optimization. By adjusting flushing parameters, the anchor can be buried to the optimal depth that provides sufficient anchoring reliability while remaining accessible for retrieval when needed, thus balancing anchoring sufficiency with retrieval ease.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Reliability

If considerable effort and costs are invested to bury anchor devices securely in the underwater bed, then anchoring security is improved, but operational costs and time consumption increase

Engineering Contradiction:
Improveanchoring securityVSAvoidinstallation efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The integrated hydraulic flushing system enables rapid burial and retrieval operations through high-pressure fluid injection. This significantly reduces the time and resources required compared to traditional mechanical excavation methods, thereby improving installation efficiency while maintaining anchoring security.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The flushing system is integrated directly into the anchor device, allowing it to perform its own burial and retrieval operations without requiring external heavy equipment. This self-service capability reduces operational costs and accelerates installation procedures.

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The flushing system simplifies the process of burying and retrieving anchor devices, enhancing their secure anchoring in the seabed and reducing the effort and costs associated with these operations, while maintaining structural integrity.

Implementation Method 1

The flushing arrangement has at least one outlet nozzle connected to the inlet opening via a fluid channel, configured to discharge the received flushing fluid

Methodology Applied
Scientific EffectLiquefaction: Phase Change

Data Source

PatentEP3950487B1Anchoring system for anchoring an offshore structure
Publication Date: 2024.05.15 RWE OFFSHORE WIND GMBH
  • EP3950487B1 patent drawingFigure 1
  • EP3950487B1 patent drawingFigure 2
  • EP3950487B1 patent drawingFigure 3

AI summary

The application relates to an anchor system (100, 200, 300, 400, 500, 600, 700) for anchoring an offshore structure (226), in particular a floatable offshore structure (226), comprising at least one anchor device (102, 202, 402, 502, 602, 702) with at least one anchor base body (104, 204, 404, 504, 604, 704), at least one flushing arrangement (106, 206, 406, 506, 606, 706) arranged in the anchor base body (104, 204, 404, 504, 604, 704), wherein the flushing arrangement (106, 206, 406, 506, 606, 706) has at least one inlet opening (108, 208, 608, 708) configured to receive a rinsing fluid, wherein the rinsing arrangement (106, 206, 406, 506, 606, 706) comprises at least one outlet nozzle (110, 210, 410, 510, 610, 710) connected to the inlet opening (108, 208, 608, 708) via a fluid channel (112, 212, 412, 512, 612, 712), configured to discharge the received rinsing fluid.